Keeping muscle with cardio

I've been doing some research on the digestion of sugar (glycolysis,krebs cycle,mitochondria, etc...). During aerobic exercise, gluclose (sugar) is digested through the mitochondria by oxidative enzymes (NADH and FADH) to produce ATP. Thus, the more sugar you eat and the more oxygen you intake, the more energy you can create. Through anaerobic exercise, the gluclose molecule cannot enter the mitochondria due to the lack of oxygen. Thus glycolysis still occurs, but it is broken down into pyruvate, which then turns into lactic acid (the burning sensation).

My question is this: When you awake, your body is in a fast. You need to eat to replenish yourself. Why is cardio more effective the first thing in the morning before eating? I understand this is the best way to burn up all the reserves of fat, but won't it eat away your muscle as well?
HOW CAN YOU PROTECT YOUR MUSCLE TISSUE FROM CATABOLISM DURING CARDIO?

I've been doing some research on the digestion of sugar (glycolysis,krebs cycle,mitochondria, etc...). During aerobic exercise, gluclose (sugar) is digested through the mitochondria by oxidative enzymes (NADH and FADH) to produce ATP. Thus, the more sugar you eat and the more oxygen you intake, the more energy you can create. Through anaerobic exercise, the gluclose molecule cannot enter the mitochondria due to the lack of oxygen. Thus glycolysis still occurs, but it is broken down into pyruvate, which then turns into lactic acid (the burning sensation).

I've been doing some research on the digestion of sugar (glycolysis,krebs cycle,mitochondria, etc...). During aerobic exercise, gluclose (sugar) is digested through the mitochondria by oxidative enzymes (NADH and FADH) to produce ATP. Thus, the more sugar you eat and the more oxygen you intake, the more energy you can create. Through anaerobic exercise, the gluclose molecule cannot enter the mitochondria due to the lack of oxygen. Thus glycolysis still occurs, but it is broken down into pyruvate, which then turns into lactic acid (the burning sensation).

My question is this: When you awake, your body is in a fast. You need to eat to replenish yourself. Why is cardio more effective the first thing in the morning before eating? I understand this is the best way to burn up all the reserves of fat, but won't it eat away your muscle as well?
HOW CAN YOU PROTECT YOUR MUSCLE TISSUE FROM CATABOLISM DURING CARDIO?

Because when done at a low intensity all available glucose will be used. Most people think this take about 20 min to accomplish. Once that glucose is gone you will tap into fat stores because the intensity is low and fat is the prefered fuel, mainly because oxygen is available. When you dip into high intensities you go from aerobic to anaerobic which means you are now in an oxygen debt and fat will not be used as fuel, as oxygen is need to oxidize fat. If you are doing this in the fasted state when glycoegn stores are low you will have no available energy source except for amino's which will be converted to glucose via gluconeogenesis. This will cause muscle loss, however is you exercise with oxygen (aerobic) you will be fine.

Because when done at a low intensity all available glucose will be used. Most people think this take about 20 min to accomplish. Once that glucose is gone you will tap into fat stores because the intensity is low and fat is the prefered fuel, mainly because oxygen is available. When you dip into high intensities you go from aerobic to anaerobic which means you are now in an oxygen debt and fat will not be used as fuel, as oxygen is need to oxidize fat. If you are doing this in the fasted state when glycoegn stores are low you will have no available energy source except for amino's which will be converted to glucose via gluconeogenesis. This will cause muscle loss, however is you exercise with oxygen (aerobic) you will be fine.

Thanks for the info guys. I'm just going to walk on the treadmill today at high incline for about 45mins. to get my heart pumping. I've heard this is an effecient way to enduce fat burning instead of amino turnover. You guys are awesome, thanx again!

Thanks for the info guys. I'm just going to walk on the treadmill today at high incline for about 45mins. to get my heart pumping. I've heard this is an effecient way to enduce fat burning instead of amino turnover. You guys are awesome, thanx again!

That's what I do three times a week first thing upon awakening on a empty stomach. I do incline treadmill with 3.5 and a incline of 6 for 40 minutes. What do you have yours set to?